Dynamo-electric machine.



PATENTED SEPT. 26, 1905.

J. P. MALLETT.

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED MAY 10, 1901.

UNITED STATES PATENT OFFICE.

JOHN P. MALLETT, OF MADISON, WISCONSIN, ASSIGNOR TO NORTHERN ELECTRICAL MANUFACTURING COMPANY, OF MADISON, WVISCONSIN, A CORPORATION OF WISCONSIN.

DYNAMO-ELECTRIC MACHINE.

No. 800,382. Specification of Letters Patent. Patented Sept. 26, 1905.

Application filed May 10, 1901. Serial No. 59,558.

To all whom it y Con/067"! the pole-piece around which the coil is wound Be itknown that I, JOHN P. MALLETT, acitican be reduced to a minimum, thus obtaining 55 Zen of the United States, residing at Madison, the greatest number of turns for a given in the county of Dane and State of \Visconsin, length of wire. The pole-pieces are connected have invented a certain new and useful Imto the field-magnet frame in any'desired manprovement in Dynamo-Electric Machines, of ner. As herein illustrated, the inner face of which the following is a specification. the frame is turned down or otherwise fin- 6 My invention relates to dynamo-electric ished so that it will have a smooth surface machines, and has for its object to provide a all the way around. The pole-pieces are then 10 new and improved machine of this description. fastened in position-as, for example, by the My invention is illustrated in the accombolts B. By finishing up the entire inner panying drawings, whereinface of the frame the poles may be positioned 5 Figure 1 is a View of a dynamo-electric maas desired and the number of pole-pieces may chine embodying my invention with parts be changed or varied in any given machine,

omitted. Fig. 2 is a view of the armaturethus permitting a standard frame to be used face of one of the pole-pieces. Fig. 3 is a secwith a varying number of pole-pieces. I also tion through one of the pole-pieces. provide an enlarged pole-face opposed to the Like letters refer to like parts throughout armature by providing the pole with a rethe several figures. movable end piece or tip C. The armature 20 I have illustrated in the drawings a conend of the pole-piece is provided with the struction of dynamo-electric machine adapted projection C, preferably circular, and haveitherfor generatorsor motors. In this coning the beveled or inclined face C The struction the cores or pole-pieces A of the removable end piece or tip C is preferably field-magnets are separated from the field made of material different from the pole- 2 5 magnet frame or ring B and are attached piece and larger, so as to compensate for the thereto in any desired manner. Such a condifference in permeability. This end piece,

struction permits the pole-pieces to be made as herein shown, is split, and the parts are of material of a different or higher permeaprovided with openings beveled to correspond bility than the material of the support. Such with the beveled face (f. The two pieces are 0 a construction has numerous advantages. If placed around the projection C and clamped the pole-pieces are of higher permeability in position by means of the bolts C the bevthan the field-magnet frame and of equal eled faces thus insuring a good contact on cross-section, the field-magnet frame becomes both of the opposed faces of the pole piece saturated before the pole-pieces, and if the and tip, for when the bolts are tightened the 35 part of the pole-piece in contact with the wedge action brings both of these faces into frame is of the same size as the cross-sectional intimate contact. This end piece when of difarea of the pole, but less than that of the ferent material concentrates the lines of force frame, the material of the frame at the surtoward the center and reduces the tendency face of contact is worked too hard and proper of the field to shift in response to the arma- 0 results cannot be obtained. In the constructure reaction. By this construction it will be tion herein shown I provide the pole-pieces seen that when the pole-pieces and the mag- A with an enlarged end A, so that the face net-frame are made of material of different of the pole in contact with the field-magnet permeability I am enabled to obtain a small frame is of a greater area than the cross-seccross-section inside of the coil and yet a suf- 45 tion of the pole-piece. The size of this enficient area on either face to allow the proper larged end depends, of course, upon the comsaturation of the different opposed elements, parative permeability of the two substances thus obtaining a maximum efficiency for the and is preferably arranged so as to compenmaterial used and the coils employed. The sate for the difference in permeability, and removable end piece or tip permits the coils 5 thus prevent the overworking of the magnetto be placed in position and obviates the neframe at. the points where the poles are atcessity of any separate holding devices for tached. These poles are preferably round or said coils, for when the pole-tips are placed [05 circular, and by this construction the part of in position they hold the coils securely in place, the beveled faces preventing any slipping or displacement thereof. \Vhen this construction is used, it will be seen that the fieldcoils may be removed from the machine separately by removing the entire pole-piece or by simply removing the end piece or tip.

I have illustrated a particular construction embodying my invention; but it is of course evident that the form and arrangement of the parts may be varied in many particulars without departing from the spirit of my invention, and I therefore do not limit myself to the construct-ion shown.

I claim- 1. A dynamo-electric machine, comprising a circular magnet-frame, one or more polepieces separate therefrom and of material having a different magnetic permeability from the material of the frame, the face of each pole-piece in contact with the frame being of greater area than the cross-section of the polepiece, so as to compensate for the difference in permeability between the two elements, the armature end of each pole-piece provided with a projecting part of smaller area than the cross-section of the pole-piece, and a removable end piece or tip presenting angularlydisposed surfaces to engage similar surfaces on the pole proper differing in magnetic permeability from the pole-piece and through Which this projecting part passes, the end piece being clamped thereto said engaging face formed by an enlarged or laterally-extended flange-like body.

2. A pole-piece for dynamo-electric machines, comprising two enlarged end pieces, having faces greater in area than the crosssection of the pole through the field-coil, one of said end pieces being removably attached to the pole-piece said end pieces having angularly-disposed surfaces to engage similar surfaces on the pole proper.

3. A pole-piece for dynamo-electric machines, provided with a removable end piece or tip forming part of the armature-face of the pole-piece, said pole-piece provided with a projection which passes through the removable tip, so as to be exposed and also form part of the face of the pole-piece opposed to the armature, said removable tip being of material of different magnetic permeability from the material of the pole-piece said end piece or tip having angularly-disposed surfaces to engage similar surfaces on the pole proper.

4. A pole-piece for dynamo-electric machines, provided at the end near the armature with a projection, having a smaller cross-sectional area than the pole-piece, the face connecting it with the pole-piece being beveled or inclined, a removable end piece or tip of material of different magnetic permeability from the pole-piece and split into two pieces so as to surround the projection on the polepiece, the engaging faces of the removable tip being beveled to correspond with the bevel of the projection, and means for clamping said two pieces around said projection so as to bring the engaging faces into intimate contact.

5. In a dynamo-electric machine, a polepiece having a reduced end, said reduced end being formed with an undercut clamping-surface and a multi part tip or end piece clamped about said reduced end against said undercut clamping-surface.

6. In a dynamo-electric machine, a polepiece formed with a beveled or undercut clamping-surface and a multipart pole-tip or end piece clamped against said surface.

7. In a dynamo-electric machine, a pole piece having a reduced end, and a multipart pole-tip or end piece clamped about said reduced end.

8. In combination, a pole-piece and a separate poletip or end piece, said tip or end piece being made in separable parts, and means for clamping said parts together to thereby secure them to the pole-piece.

9. In a dynamo-electric machine, a polepiece and a pole-tip or end piece formed in parts, said parts each having a clamping-surface engaging the pole-piece, and means for forcing the parts together to clamp them to the pole-piece.

10. In a dynamo-electric machine, a polepiece and a multipart pole-tip or end piece embracing said pole-piece, and means for clamping the parts of the tip or end piece together to locl; them to the pole-piece.

11. In a dynamo-electric machine, a poletip or end piece formed in two separable parts each of which have engaging surfaces, a polepiece and means for clamping the pole-piece between the engaging surfaces of the pole-tip or end piece.

JOHN P. MA LLE'I" Witnesses:

F. M. CoNLnE, A. J. BUENZLI. 

